@media screen and (min-width:1200px) {
  html {
    font-size: 25px;
  }
}

@media screen and (min-width:800px) and (max-width:1200px) {
  html {
    font-size: 20px;
  }
}

@media screen and (max-width:800px) {
  html {
    font-size: 15px;
  }
}

* {
  margin: 0;
  padding: 0;
  font-family: '幼圆';
}

html,
body {
  height: 100%;
  width: 100%;
}

div {
  width: 36rem;
  height: 2.2rem;
  border-bottom: 0.1rem solid #303133;
  margin: 5rem auto;
}

div ul li {
  list-style: none;
  float: left;
}

div ul li a {
  width: 5rem;
  height: 2rem;
  display: block;
  border: 0.05rem solid #DCDFE6;
  margin: 0 0.5rem;
  margin-top: 0.1rem;
  /* 初始状态  存在margin-top:0.1rem; */
  border-bottom: none;
  text-align: center;
  line-height: 2rem;
  color: #909399;
  background-color: #F2F6FC;
  text-decoration: none;
  transition: all 1s;
}

div ul li a:hover {
  color: white;
  background-color: rgba(0, 0, 0, .8);
}

.active {
  height: 2.2rem;
  border: 0.1rem solid #303133;
  border-bottom: none;
  color: #409EFF;
  margin-top: 0;
  /* 最终状态  存在margin-top:0; */
  background-color: white;
}